1. Field of the Invention
The present invention relates to a tool holding device for a bit and, in particular, the tool holding device is suitable to have an application with a power tool.
2. Description of the Related Art
U.S. Pat. No. 6,345,560 teaches a clamping chuck including a toolholder in which a bit is adapted to be received. Preferably, the bit has a shank of a standard hexagonal shape and a plurality of recesses disposed thereon. A clamping portion with a hexagonal cross section is connectable to a drive member. An actuating sleeve is connected to the toolholder and is utilized to maneuver a ball to selectively engage in and disengage from one of the recesses in the received bit. Thus, when the ball is engaged in one of the recesses, the received bit is securely retained in the toolholder, and when the ball is disengaged from the recess, the received bit is removable from the toolholder. It is appreciated that the actuating sleeve has a front end with a gradually decreasing outer diameter so if driving a fastener in a hole, a user may insert a portion of the front end of the sleeve which can clear the hole in order that the bit can engage with the fastener. However, if the front end is inserted in the hole and the bit still can't engage with the fastener, the user then has to use a bit with an elongated shank. Further, the user has to hold the elongated shank to alleviate a wobble of the bit during operation, particularly when the bit is rotated by a power tool rapidly.
Also, it is understood that when the received bit is allowed to be removed from the toolholder, the received bit can fall out of the toolholder due to gravity. Therefore, U.S. Pat. No. 6,345,560 teaches a magnet disposed in the toolholder adapted to relieve this problem. However, it is noted that the toolholder and other elements in the toolholder, any of which that are magnetizable, can scatter and, therefore, weaken the magnetic force. Thus, the magnet no longer provides sufficient force to hold the bit from falling out due to gravity.
Another chuck device for tool bits is disclosed in U.S. Pat. No. 6,637,755. However, this chuck device does not help the user reduce the demand of using a bit with an elongated shank.
In addition, U.S. Pat. No. 6,637,755 teaches a pusher utilized to facilitate removal of the bit received in the chuck device. However, if the user does not hold the bit, the bit will drop out of the chuck device. The user, then, has to pick up the bit which will result an inconvenience.
The present invention is, therefore, intended to obviate or at least alleviate the problems encountered in the prior art.